The asteroid that hit the Earth around 66 million years ago, effectively wiping out the dinosaur population, brought cosmic cancer-killing metals to Earth, according to a new study. Scientists found that by filling iridium — a metal delivered by the asteroid — with a kind of poisonous oxygen, cancer cells can be destroyed, without having any harmful effects on healthy cells.

Scientists at the the University of Warwick and Sun Yat-Sen University in China developed a new method to destroy cancer cells using the silvery metal iridium. The metal is the second densest element and can endure temperatures as high as 2,400 Celsius.

The scientists created a model tumour of lung cancer in the lab. They also developed a compound of iridium and organic material, which when injected into cancer cells, changes the oxygen into a poison called singlet oxygen, eventually destroying the cancerous cells.

The researchers used a laser light to activate the iridium injected into the cancer cells, only to discover that the singlet oxygen infiltrated every layer of the tumour and eradicated it. The new research, published in the journal Angewandte Chemie, is still in very early stages and has so far only been used on a model of cancerous cells. However, the new study still offers a new perspective on this kind of cancer treatment.

"This project is a leap forward in understanding how these new iridium-based anti-cancer compounds are attacking cancer cells, introducing different mechanisms of action, to get around the resistance issue and tackle cancer from a different angle," Cookson Chiu from the University of Warwick, who is the co-author of the study, said in a statement.

According to Peter Sadler, also from Warwick, over 50% of cancer chemotherapies already make use of platinum. This means that there is some potential for other precious metals like iridium to provide "new targeted drugs" that attack cancer cells. Sadler said, "It's certainly now time to try to make good medical use of the iridium delivered to us by an asteroid 66 million years ago!"

"Our innovative approach to tackle cancer involving targeting important cellular proteins can lead to novel drugs with new mechanisms of action," Dr Pingyu Zhang from Warwick said. "These are urgently needed."